iOS 10 Programming for Beginners

Control flow

In programming, control flow is the order in which your code is executed. When working with Swift, we can use a variety of control statements. Loops, in particular, are useful for when you want to repeat a task multiple times. Let's take a look at a few different types of loop.

The for…in loop

One of the most common control statements is a for…in loop. It allows you to iterate over each element in a sequence. Let's see what a for…in loop looks like:

for <value> in <sequence>  {
  // Code here
}

We start the for…in loop with for, which is proceeded by <value>. This is actually a local constant (only the for…in loop can access it) and can be any name you like. Typically, you will want to give this value an expressive name. Next, we have